The energy recovered free electron laser (FEL) at Jefferson Laboratories in Newport News, Va. accelerates an electron beam in superconducting cavities and transfers it through a wiggler to produce light pulses and returns it to the beginning of the superconducting cavities at a phase that decelerates the beam so that energy is returned to the cavities. The light pulses from the wiggler are contained in an optical resonator (a pair of mirrors spaced a precise multiple of the bunch separation) that synchronously reflects the light back to the wiggler to a later electron bunch to provide stimulated, amplified light emissions.
While free electron lasers associated with large particle accelerators such as that at the Jefferson Laboratory in Newport News, Va. provide highly useful research tools, such devices, largely because of their cost and size are not widely available in, for example, universities or small research institutes.
Accordingly, the development of a compact high power free electron laser capable of producing tuneable coherent light would open experimentation with such devices to a much broader class of investigators and could result in the development of even more useful applications thereof.